Jeff's 727 rebuild thread
With the tab on the throttle lever cam on the wrong side of the screw head, the cam cannot contact the Kick down valve. So like Dave stated in post 459, when you push the gas pedal down, the throttle lever cam pushes the kick down valve into the valve body against the throttle valve spring increasing line pressure. Without this increase in line pressure, the clamping force on the clutches is insufficient & under heavy acceleration the clutches will slip.
Check the weld on the throttle lever/cam. I've had a couple of these fail. Then the throttle lever will turn but the cam doesn't. If it checks out air pressure check the transmission & put the VB back in. I think you got it.